KDE 4.1 API Reference soprano
Soprano (aka QRDF) - A modular RDF storage framework
Soprano is a QT-based pluggable framework for RDF storage and parsing. It tries to provide a highly usable interface to several RDF storage solutions.
Overview
Soprano centers around the Soprano::Model class which represents one storage set. A Soprano::Model is basically a set of RDF quadruples, i.e. Soprano::Statement. The actual storage is done via Soprano::Backend plugins. All query operations return Soprano::Iterator instances. Iterator is a explicitely shared class which is very easy to understand and use.Soprano makes the distinction between two types of Models: Soprano::StorageModel and Soprano::FilterModel. The former one is intended to be the basic Model which actually stores the data while the latter ones can be stacked on top of a Soprano::StorageModel to perform certain filter operations. Thes filter operations can range from very basic things such as disallowing any write operation (Soprano::Util::ReadOnlyModel) to more complex things such as full text indexing of all literal statements (Soprano::Index::IndexFilterModel) or exporting the Model via D-Bus (Soprano::Server::DBusExportModel).
Apart from storage Soprano provides a system for RDF parser and serializer plugins. For more details on parsing or serializing RDF data see the Soprano::Parser and Soprano::Serializer classes.
Quickstart
Create an RDF Model:
Soprano::Model* model = Soprano::createModel();
Fill it with statements:
model->addStatement( Soprano::Statement( QUrl( "http://mysite.org/data#A"), Soprano::Vocabulary::RDFS::label(), Soprano::LiteralValue( "A test resource" ) ) );
Read the data back:
Soprano::StatementIterator it = model->listStatements(); while( it.next() ) { displayStatement( *it ); }
Query the data:
Soprano::QueryResultIterator it = model->executeQuery( "select ?r where { ?r ?p ?o . }", Soprano::Query::QueryLanguageSparql ); while( it.next() ) { displayResult( it.binding( "r" ) ); }
Contents
The following sections contain further information on the usage of Soprano.
